Clutch cover and releasable bearing assembly

ABSTRACT

A clutch cover assembly has a clutch cover adapted to be coupled to a flywheel of an engine, a pressure plate disposed inwardly of the clutch cover, a diaphragm spring having an outer edge engaged by the clutch cover for resiliently pressing the pressure plate, a bearing fixed to an inner edge of the diaphragm spring and having rotatable elements and an inner race supporting the rotatable elements, a bearing hub axially movably disposed in the bearing for being axially movably disposed on an input shaft of a transmission, a locking member disposed between the inner race and the bearing hub for locking the bearing hub against movement with respect to the bearing away from the engine, and a release fork engageable with the bearing hub for axially moving the bearing hub and the bearing away from the engine to release the pressure plate from the diaphragm spring. For dismounting the transmission from the engine, the bearing hub is moved with respect to the bearing toward the engine to allow easy detachment of the input shaft of the transmission. Alternatively, the locking member may disengage from the bearing to permit removal of the bearing hub from the bearing for easy detachment of the transmission input shaft.

This application is a divisional of application Ser. No. 032,387, filedMar. 31, 1987 now U.S. Pat. No. 4,830,162.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to a clutch cover assembly of the pulltype.

2. Description of the Prior Art

As shown in FIG. 13 of the accompanying drawings, one conventionalclutch cover assembly coupled to an engine comprises a clutch cover 110,a pressure plate 120 disposed inwardly of the clutch cover 110, adiaphragm spring 130 having an outer edge engaged by the clutch cover110 for pressing the pressure plate 120, a bearing 140 secured to aninner edge of the diaphragm spring 130 and holding rotatable elements145, a bearing hub 160 integral with the inner race 143 of the bearing140, and a release fork (not shown) for axially moving the bearing hub160 away from the pressure plate 120 to release the pressure plate 120from the pressure of the diaphragm spring 130.

The bearing hub 160 and the bearing 140 are of a unitary structure, andthe bearing hub 160 projects from the bearing hub 160 toward atransmission (not shown).

When disassembling the transmission from the engine, the tip end of theinput shaft of the transmission is slid up to the end face of thebearing hub 160 so that the input shaft can be removed clear of thebearing hub 160. Therefore, it is necessary for the clutch coverassembly to have a large space to allow the input shaft of thetransmission to slide therein for detachment.

SUMMARY OF THE PRESENT INVENTION

In view of the aforesaid drawback of the conventional clutch coverassembly, it is an object of the present invention to provide a clutchcover assembly which does not require a large space to allow atransmission to slide therein when the transmission is to be dismountedfrom an associated engine.

Another object of the present invention is to provide a clutch coverassembly capable of allowing easy detachment of a transmission from anassociated engine.

According to the present invention, there is provided a clutch coverassembly including a clutch cover adapted to be coupled to a flywheel ofan engine, a pressure plate disposed inwardly of the clutch cover, adiaphragm spring having an outer edge engaged by the clutch cover forresiliently pressing the pressure plate, a bearing fixed to an inneredge of the diaphragm spring and having rotatable elements and an innerrace supporting the rotatable elements. A bearing hub is axially movablydisposed in the bearing for being axially movably disposed on an inputshaft of a transmission and a locking member is disposed between theinner race and the bearing hub for locking the bearing hub againstmovement with respect to the bearing away from the engine. A releasefork is engageable with the bearing hub for axially moving the bearinghub and the bearing away from the engine to release the pressure platefrom the diaphragm spring.

According to a first embodiment of the present invention, the lockingmember comprises at least one key disposed between the bearing hub andthe inner race and a pair of snap rings at opposite ends of the key. Oneof the snap rings is retained on the bearing hub and the other snap ringis retained on the bearing, whereby the bearing hub is axially movablewith respect to the bearing toward the engine.

According to another embodiment of the present invention, the inner racehas a groove defined in an inner periphery thereof. The locking membercomprises at least one lock spring having one end fixed to the bearinghub and an opposite end normally engaging in the groove of the innerrace, whereby the bearing hub is axially movable away from the enginewhen the opposite end of the locking spring is displaced out of thegroove. The lock spring has a central raised portion, the opposite endthereof having a hook portion integral with or fixed to the centralraised portion and normally engaging in the groove. The hook portion isdisplaceable out of the groove by pushing the central raised portiontoward the bearing hub.

In one preferred embodiment, the locking member is disengageable fromthe bearing to allow the bearing hub to disengage from the bearing. In apreferred embodiment, the clutch cover assembly includes a lockingdevice mounted on the release fork for locking the bearing hub withrespect to the bearing, and a ring member disposed around the bearinghub and movable by the release fork, the locking device being unlockableto allow the release fork to move the ring member toward the engine fordisengaging the locking member from the bearing.

The above and other objects, features and advantages of the presentinvention will become more apparent from the following description whentaken in conjunction with the accompanying drawings in which preferredembodiments of the present invention are shown by way of illustrativeexample.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will be described withreference to the accompanying drawings wherein, like or correspondingparts are denoted by like or corresponding reference numerals throughoutthe several drawing figures, and wherein:

FIG. 1 is a fragmentary, vertical cross-sectional view of a clutch coverassembly according to a first embodiment of the present invention;

FIG. 2 is a fragmentary, front elevational view of the clutch coverassembly as viewed from an engine;

FIG. 3 is a fragmentary, vertical cross-sectional view of a clutch coverassembly according to a modification of the first embodiment;

FIG. 4 is a fragmentary, vertical cross-sectional view of a clutch coverassembly according to a second embodiment of tne present invention;

FIG. 5 is an exploded perspective view of a bearing hub and a lockingmember of the clutch cover assembly of FIG. 4;

FIG. 6 is a perspective view of a modified locking member;

FIGS. 7 and 8 are fragmentary, vertical cross-sectional views of clutchcover assemblies according to modifications of the second embodiment;

FIG. 9 is a fragmentary, vertical cross-sectional view of a clutch coverassembly according to a third embodiment of the present invention;

FIG. 10 is an elevational view of a release fork taken along line X--Xof FIG. 9;

FIG. 11 is an exploded perspective view of a bearing hub and a lockingmember of the clutch cover assembly of FIG. 9;

FIG. 12 is a fragmentary, vertical cross-sectional view of a clutchcover assembly according to a modification of the third embodiment; and

FIG. 13 is a vertical cross-sectional view of a conventional clutchcover assembly of the prior art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 1st Embodiment

With reference to FIGS. 1 and 2, a clutch cover assembly according to afirst embodiment includes a clutch cover 10, a pressure plate 20, adiaphragm spring 30, a bearing 40, a bearing hub 60, a locking member70, and a release fork 80. The locking member 70 includes keys 71 andsnap rings 72, 73.

The clutch cover assembly is disposed between an engine (not shown) anda transmission (not shown). The clutch cover 10 has an axial sideopposite to the engine that is fastened to a flywheel (not shown) bybolts. The pressure plate 20 is disposed within the clutch cover 10 forpressing the friction surface of a clutch disc (not shown). The clutchcover 10 has an end opposite to the transmission and coupled by a wirering 11 to the outer edge of the diaphragm spring 30. The diaphragmspring 30 has an inner edge fixed to the outer race of the bearing 40.The diaphragm spring 30 in its intermediate position resiliently pressesthe pressure plate 20 toward the engine, the pressure plate 20 beingpositioned more closely than the diaphragm spring 30 to the engine. Thebearing 40 serves to take up relative rotation of the pressure plate 20rotating with the flywheel and the bearing hub 60. The bearing hub 60 isaxially movably inserted in the bearing 40. The bearing hub 60 has aflange 62 on its end closer to the transmission, the flange 62 beingengaged by upper free ends of the release fork 80 at an end surfacefacing the engine.

The bearing hub 60 is joined to the inner race 43 of the bearing 40 bymeans of the locking member 70, i.e., three keys 71 (see FIG. 2) and twosnap rings 72, 73. The keys 71 are fitted respectively in threeangularly spaced key slots defined axially on the outer peripheralsurface of the bearing hub 60 at its axial end portion closer to theengine. The snap rings 72, 73 are disposed around the bearing hub 60against the axially opposite ends of the keys 71 inserted in the keyslots. The snap ring 72, closer to the engine, is disposed in an annulargroove defined in the bearing hub 60 substantially up to a half of thethickness of the snap ring 72. The other snap ring 73, closer to thetransmission, is disposed in an annular groove defined in the inner race43 substantially up to a half of the thickness of the snap ring 73. Withthis arrangement, the keys 71 are prevented by the snap ring 73 frommoving beyond the inner race 43 toward the transmission, but are allowedto move toward the engine.

When the release fork 80 is turned clockwise (FIG. 1), the clutch isdisengaged. More specifically, when the bearing hub 60 is moved towardthe transmission, the bearing 40 is also moved toward the transmissionsince the bearing hub 60 and the bearing 40 are fastened together by thekeys 71 and the snap rings 72, 73. Therefore, the diaphragm spring 30which has been pressed against the pressure plate 20 is released frompressing engagement with the pressure plate 20.

For dismounting the transmission from the engine, the release fork 80 isremoved away from the flange 62 of the bearing hub 60. The bearing hub60 can now be slid toward the engine since the keys 71 are disengagedfrom the snap ring 73. With the bearing hub 60 thus displaced toward theengine for a predetermined distance as indicated by the broken line inFIG. 1, the distance, an input shaft of the transmission must be pulledaway from the engine to remove the shaft is reduced by the samepredetermined distance. Accordingly, the clutch cover assembly requiresno wide space in which to slide the input shaft of the transmission fordetachment. When the transmission is to be mounted on the engine, theinput shaft thereof can be pushed toward the engine with the bearing hub60 slid toward the engine. Thus, the transmission can easily bepositioned in place.

With reference to FIG. 3, a modification of the first embodimentincludes a sleeve 76 is interposed between the inner race 43 of thebearing 40 and the bearing hub 60. The sleeve 76 is fixed to the innerrace 43 by snap rings 74, 75 held against axially opposite ends of thesleeve 76. The snap ring 73 is disposed in an annular groove defined inthe sleeve 76. The arrangement of FIG. 3 is advantageous in that thebearing 40 may be of a commercially available standard design inasmuchas its inner race 43 is not required to have an annular groove forreceiving the snap ring 73 and can simply be attached to the sleeve 76by the snap rings 74, 75.

2nd Embodiment

FIGS. 4 and 5 illustrate a clutch cover assembly according to a secondembodiment of the present invention. The clutch cover assembly of FIGS.4 and 5 employs a different locking member from that of the firstembodiment. The locking member of the second embodiment comprises twolock springs 90 mounted on the bearing hub 60 in diametrically oppositerelation, i.e., 180° from each other about the hub 60. Each of the locksprings 90 has a central raised portion 91 displaced laterally, i.e.,perpendicular to the longitudinal axis of the spring 90 and a hookportion 92 which is bent substantially perpendicularly from one end ofthe lock spring 90 in the same direction as that in which the raisedportion 91 is displaced. The opposite end of the lock spring 90, remotefrom the hook portion 92, is fastened to the bearing hub 60 by tworivets 93. The hook portion 92 engages a groove defined in the innerperiphery of the inner race 43.

FIG. 6 shows a modification in which a lock spring 90a has a separatehook portion 92a fastened to a raised portion 91a.

During normal usage of the clutch cover assembly, the inner race 43 andthe bearing hub 60 are held in locked engagement with each other by thelock springs 90. Therefore, the clutch can be disengaged by turning therelease fork 80 clockwise (FIG. 4). The bearing hub 60 can be disengagedfrom the inner race 43 simply by manually depressing the raised portion91 (or 91a) of each lock spring 90 (or 90a) radially inwardly todisplace the hook portion 92 (or 92a) out of the groove in the innerrace 43. With the bearing hub 60 thus disengaged from the inner race 43,the bearing hub 60 can be slid toward the transmission and removed fromthe bearing 40. After the bearing hub 60 has been detached, thetransmission can easily be dismounted from the engine, and no wide spaceis required in the clutch cover assembly for such detachment of thetransmission.

FIG. 7 shows a modified clutch cover assembly which additionally employsa sleeve 76' disposed between the inner race 43 and the bearing hub 60and secured to the inner race 43 by snap rings 74, 75, as with themodification of FIG. 3. The bearing 40 can thus be of a commerciallyavailable standard configuration.

According to another modification shown in FIG. 8, a locking membercomprises a lock spring 90b having on one end thereof a hook portion 92bengaging in a groove defined in the outer periphery of the inner race43' of the bearing 40. The lock spring 90b is fastened to a raisedportion 64 on the outer periphery of the bearing hub 60.

3rd Embodiment

With reference to FIG. 9, a clutch cover assembly according to a thirdembodiment of the present invention includes a clutch cover (not shown),a pressure plate (not shown), a diaphragm spring 30, a bearing 40, abearing hub 60, a locking member 90c, a release fork 80, and a ringmember 50. The clutch cover, the pressure plate, the diaphragm spring30, the bearing 40, the bearing hub 60, and the release fork 80 aresubstantially identical to those of FIG. 1 and will not be described indetail.

The locking member 90c comprises two lock springs as shown in FIG. 11. Alocking device 82 is mounted on the release fork 80.

The inner race 43 of the bearing 40 has grooves 44 in which therespective lock springs 90c engage. Each of the lock springs 90c has oneend fastened to the outer periphery of the bearing hub 60 by two rivets93 (FIG. 11). The lock spring 90c has a central raised portion 91cdisplaced laterally and a tooth 92c projecting, by lancing, from theopposite end in the same direction as that in which the raised portion91c is laterally displaced. The tooth 92c engages in one of the grooves44 of the inner race 43. Alternatively, the locking member may be thetype of lock spring as shown in FIG. 5.

With reference to FIGS. 9 and 10, the locking device 82 includes twolock levers 84 pivotally mounted by respective bolts 83 on the two forkarms of the release fork 80, the lock levers 84 being angularly movablein planes parallel to the axis of the bearing hub 60. Each of the locklevers 84 is of a flat plate substantially in an S shape. The free endof each lock lever 84 is positioned on one side of the flange 62 closerto the transmission. The other ends of the lock levers 84 areinterconnected by a substantially V-shaped wire 85 with its intermediateportion engaging in a selected one of spaced slots 81 defined in thelower end of the release lever 80.

With the wire 85 under tension. the flange 62 is gripped between thefree ends of the lock levers 84 and the free ends of the release fork80. When the wire 85 is released of tension, the free ends of the locklevers 84 are displaced off the flange 62, leaving a gap a therebetween.The wire 85 is normally fixed to the release fork 80 by one of the slots81 with springs 86 acting between the lock levers 84 and the releasefork 80 for normally urging the lock levers 84 in a direction todisengage from the flange 62. A ring member 50 which is disposed aroundthe bearing hub 60 is limited in movement by the raised portions 91c ofthe lock springs 90c and the flange 62.

The clutch is disengaged by turning the release fork 80 clockwise (FIG.9). More specifically, as the bearing hub 60 is moved toward thetransmission, the bearing 40 is also moved toward the transmission sincethe bearing 40 engages the bearing hub 60 through the lock springs 90c.The diaphragm spring 30 is also displaced to release the pressure plate,thus disconnecting the clutch. The clutch can be connected again byturning the release fork 80 counterclockwise, thus moving the bearinghub 60, the bearing 40, and the diaphragm spring 30 back toward theengine to press the pressure plate.

For detaching the transmission from the engine, the wire 85 is releasedfrom the release fork 80 to unlock the locking device 82, whereupon thelock levers 84 are disengaged from the flange 62 with the gap a lefttherebetween. Then, the upper free ends of the release fork 80 areaxially moved leftward toward the engine to axially displace the ringmember 50 toward the engine by the distance equal to the gap a. The ringmember 50 pushes the raised portions 91c of the lock springs 90cradially inwardly until the teeth 92c of the lock springs 90c aredisplaced radially inwardly out of the grooves 44 of the inner race 43,whereupon the bearing 40 and the bearing hub 60 are disengaged from eachother. Thereafter, the upper free ends of the release fork 80 are movedrightward away from the engine to pull the bearing hub 60 from thebearing 40. The transmission can now be disassembled from the engine. Atthis time, the input shaft of the transmission only needs to be slid upto the end face of the bearing 40 which faces the transmission.Therefore, no large space is required in the clutch cover assembly forremoval of the transmission.

FIG. 12 shows a modified attachment of the locking device 84. Therelease fork 80 has an internally threaded hole 94 defined in the lowerend thereof, and a bolt 95 is threaded in the hole 94. The bolt 95 has ahole 96 defined in an end thereof, and the intermediate portion of thewire 85 is inserted through the hole 96 of the bolt 95. The clutch coverassembly shown in FIG. 12 employs the locking member 90 shown in FIGS. 4and 5.

The flange 62 is gripped by the release fork 80 and the lock levers 84by tightening the bolt 95, and released from engagement with the locklevers 84 by loosening the bolt 95.

Although certain preferred embodiments have been shown and described,the invention which is intended to be protected is not to be construedas limited to particular embodiments disclosed It is to be understoodthat many changes and modifications may be made therein withoutdeparting from the scope of the appended claims.

What is claimed is:
 1. A clutch cover and releasable bearing assembly,comprising:a clutch cover; a pressure plate disposed inwardly of saidclutch cover; a diaphragm spring having an outer edge engaged by saidclutch cover for resiliently pressing said pressure plate; a bearingfixed to an inner edge of said diaphragm spring and having rotatableelements and an inner race supporting said rotatable elements; a bearinghub axially movably disposed in said bearing for being axially movablydisposed on an input shaft of a transmission; a sleeve fixed to saidinner race between said inner race and said bearing hub; locking meansdisposed between said sleeve and said bearing hub for selectivelylimiting movement of said bearing hub with respect to said bearing, saidlocking means including at least one key disposed between said bearinghub and said sleeve, and a pair of snap rings at opposite ends of saidkey, one of said pair of snap rings being retained on said bearing huband the other of said snap rings being retained on said sleeve; wherebysaid bearing hub is axially movable with respect to said bearing in afirst direction; and a release fork engageable with said bearing hub foraxially moving said bearing hub and said bearing in a second directionto release said diaphragm spring from said pressure plate.
 2. A clutchcover and releasable bearing assembly comprising:a clutch cover; apressure plate disposed inwardly of said clutch cover; a diaphragmspring having an outer edge engaged by said clutch cover for resilientlypressing said pressure plate; a bearing fixed to an inner edge of saiddiaphragm spring and having rotatable elements and an inner racesupporting said rotatable elements; a bearing tub axially movablydisposed in said bearing for being axially movably disposed on an inputshaft of a transmission; locking means disposed between said inner raceand said bearing hub for selectively limiting movement of said bearinghub with respect to said bearing, said locking means including at leastone key positioned between said bearing hub and said inner race and apair of snap rings at opposite ends of said key, one of said snap ringsbeing retained on said bearing hub and the other snap rings beingretained on a part of said bearing, whereby said bearing hub is axiallymovable with respect to said bearing in a first direction; and a releasefork engageable with said bearing hub for axially moving said bearinghub and said bearing in a second direction to release said diaphragmspring from said pressure plate.